What's really at stake here is not mood but relevance. A poem may deal with whimsical or solemn topics, so long as it connects with the reader. The mainstream of poetry has careened off the cultural cliff long since, to the point that most people don't even notice it anymore. It's completely outside their sphere of experience, so it doesn't exist for them.
Yet people are still writing poetry that is lively and gripping. They're just doing it in places that don't get a great deal of official attention. Anyone who likes poetry can, with a little determination, quickly find sources that interest them. There's quite a lot of poetry online these days, although of course much of it is crap; one just has to do a bit more digging to find poets with skill. Outside of academia, people write poetry to express ideas, not to impress people. Memorialize something important. Play with language. Tell a story, tell a joke. Touch something in the reader's experience. Then people will want to read it.
But hey, at least a major magazine admitted that academic poetry is boring and irrelevant.